Effect of heat treatment on the structure and hardness of high-entropy alloys CoCrFeNiMnVx (x = 0.25, 0.5, 0.75, 1)
- Authors: Shaysultanov D.G.1, Stepanov N.D.1, Salishchev G.A.1, Tikhonovsky M.A.2
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Affiliations:
- Belgorod National Research University
- Kharkov Institute of Physics and Technology
- Issue: Vol 118, No 6 (2017)
- Pages: 579-590
- Section: Structure, Phase Transformations, and Diffusion
- URL: https://journals.rcsi.science/0031-918X/article/view/167101
- DOI: https://doi.org/10.1134/S0031918X17060084
- ID: 167101
Cite item
Abstract
High-entropy alloys CoCrFeNiMnVKharkov Institute of Physics and Technology, ul. Akademicheskaya 1, Kharkov 61108 (Kharkov Institute of Physics and Technology, ul. Akademicheskaya 1, Kharkov 61108 = 0.25, 0.5, 0.75, 1) were prepared by vacuum arc melting. The structure and microhardness of the alloys have been studied in the cast state and after annealing at temperatures of 700–1100°C. It has been found that the alloys consist of the fcc (γ) solid solution and intermetallic sigma (σ) phase. The volume fraction of the σ phase increases with increasing vanadium content. As a result of annealing, phase transformations occur, including the precipitation of σ particles from the γ phase and, vice versa, the precipitation of γ particles from the σ phase. It has been shown that the change in the volume fraction of the σ phase upon annealing occurs due to the changes in the total content of σ-forming elements, chromium and vanadium, in accordance with the lever rule. With increasing temperature, the volume fraction of the σ phase varies nonmonotonically; first, it increases, then it decreases. The microhardness of the alloys correlates well with the change in the volume fraction of the σ phase. The mechanisms of the phase transformations and quantitative relationships between chemical and phase compositions of the alloys and their hardness are discussed.
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About the authors
D. G. Shaysultanov
Belgorod National Research University
Author for correspondence.
Email: shaysultanov@bsu.edu.ru
Russian Federation, ul. Pobedy 85, Belgorod, 308015
N. D. Stepanov
Belgorod National Research University
Email: shaysultanov@bsu.edu.ru
Russian Federation, ul. Pobedy 85, Belgorod, 308015
G. A. Salishchev
Belgorod National Research University
Email: shaysultanov@bsu.edu.ru
Russian Federation, ul. Pobedy 85, Belgorod, 308015
M. A. Tikhonovsky
Kharkov Institute of Physics and Technology
Email: shaysultanov@bsu.edu.ru
Ukraine, ul. Akademicheskaya 1, Kharkov, 61108